1. Field of the Invention
The present invention generally relates to a processing apparatus which processes a substrate and, more particularly, to a processing apparatus which processes two surfaces of a substrate.
2. Description of the Related Art
A processing apparatus which simultaneously deposits films on the two surfaces of a substrate such as a hard disk medium performs processes such as sputtering while sequentially conveying each substrate held on a substrate holder into a vacuum vessel, as disclosed in Japanese Patent Laid-Open Nos. 8-13143 and 11-29150. At this time, thin films originating from a process adhere to the inner wall of the vacuum vessel and units and the like arranged inside the vacuum vessel. As such a thin film increases in thickness to some extent, the film peels off from the adhesion position and becomes particles.
In general, in order to prevent thin films from adhering to the inner wall of a vacuum vessel and units and the like, in a processing apparatus, replaceable shields to which thin films are made to adhere are arranged in a vacuum vessel to suppress the generation of particles.
According to the related art, many (at least about 10) shields are combined and arranged in a vacuum vessel to prevent thin films from adhering to the inner wall of the vacuum vessel and units and the like. However, since such shields are components to be periodically replaced, the use of many shields will lead to more complicated maintenance and higher maintenance cost.